The performance of Internet-based applications on mobile computing devices is affected by the capabilities of the underlying network technologies. To provide access to the Internet for applications on mobile devices, cellular wireless communication systems are widely deployed also referred to as radio access technology network. Such systems may be multiple-access systems able to support communication with multiple users by sharing system resources such as bandwidth and transmission power. Commonly used multiple-access systems include, but are not limited to, Code-Division Multiple Access systems, Time-Division Multiple Access systems, Frequency-Division Multiple Access, 3rd Generation Partnership Project Long Term Evolution systems, Long Term Evolution Advanced systems, Orthogonal Frequency-Division Multiple Access systems, and the like.
Additionally or alternatively, a wireless mobile computing device, such as user equipment (UE), may connect to data communications networks via a different radio access technology network such as a WLAN. Example WLAN networks include, but are not limited to, Wi-Fi networks, home WLANs, WLAN hotspots, public WLANs, private WLANs, and the like.
With an increasing number of mobile computing devices featuring WLAN-connectivity capability and with access to WLAN networks becoming more widely available, offloading data capabilities from a cellular network to a WLAN has emerged as an attractive feature for both cellular network operators and users.
3GPP specs currently support Internet Protocol (IP) packet flow mobility (see for example TS 23.261 incorporated herein by reference) but they require complicated protocols in the user equipment (UE) and gateway (PGW) (DSMIPv6) and they enable only UE-initiated IP flow mobility. However, many operators have expressed a strong need for network-initiated IP flow mobility.
The “IP flow mobility” is essentially a handover operation that applies to a specific IP flow only (e.g. to all packets with protocol=TCP and port=80). This is illustrated in the following FIGS. 1 and 2 which show that the result of an IP flow mobility procedure is IP flow #2 being transferred from a first radio access technology (RAT) network, such as 3GPP access interface to a second and different radio access technology network interface such as a WLAN access interface.
FIG. 1 illustrates one example of a system 100 that includes a packet gateway 102 in communication with user equipment 104 that are in communication using a wireless radio access technology network 106, such as a cellular network, and a different wireless radio access technology network 108 such as a wireless local area network. One of the most popular uses for wireless devices is accessing packet-data networks (PDNs), the most famous example of which is the Internet. In third generation partnership project (3GPP) networks, the user equipment (UE) can have one or more PDN connections. The UE can establish a PDN connection using different types of radio access technologies. In this example, the radio access technology network 106 is shown to be a 3GPP radio access technology network such that the UE 104 includes a 3GPP transceiver 110 and the PGW 102 utilizes a corresponding interface. The UE 104 also includes a WLAN transceiver 112 to communicate via the network 108 with the PGW 102. The PGW 102 likewise has a corresponding WLAN interface. The WLAN may be an Institute for Electrical and Electronics Engineers (IEEE) 802.11 Family of Standards Compliant Network. The PGW may be part of a network as known in the art.
FIG. 1 also illustrates uplink packets of IP flow #2 transmitted by the UE 104 and being received by the PGW 102 via 3GPP access network 106 and downlink IP flow packets #2 transmitted by the PGW 102 and being received by the UE 104 via 3GPP access network 106. This is before IP flow mobility occurs. The UE includes one or more processors and associated memory wherein the memory stores executable instructions that when executed by the processor, cause the processor to operate in a particular manner. In this example, the UE is shown to include applications 114 that may be stored in memory, for example, as well as a networking stack module 116 which may be the processor executing networking stack instructions. In addition, the UE may include a traffic steering module 118 that may also be a processor executing traffic steering instructions. As shown, before IP flow mobility is activated, all the packets of multiple packet flows occur over the 3GPP access network 106.
Most solutions in prior art enable an IP flow to be transferred from one RAT access to a different RAT access by exchanging routing rules between the UE and the gateway (PGW). For example, referring to FIG. 2, when the UE wants to transfer IP flow #2 from 3GPP access network 106 to WLAN access network 108, it sends a new routing rule to the PGW that indicates to route all downlink packets of IP flow #2 to WLAN 108. The PGW responds to the UE by indicating if the new routing rule was applied or was rejected. However, exchanging routing rules between the UE and the PGW is very complicated: It requires new signaling between the UE and MME, between MME and SGW, between SGW and PGW, etc. Apparently, exchanging routing rules between the UE and PGW has a big system-wide impact and may result in expensive deployments.